source: libcfa/src/concurrency/kernel.cfa@ fb15af5

ADT arm-eh ast-experimental enum forall-pointer-decay jacob/cs343-translation new-ast-unique-expr pthread-emulation qualifiedEnum
Last change on this file since fb15af5 was da3963a, checked in by Thierry Delisle <tdelisle@…>, 5 years ago

Moved bin_sem_t out of kernel.hfa since it's not needed.
  • Property mode set to 100644
File size: 23.1 KB
Line 
1//
2// Cforall Version 1.0.0 Copyright (C) 2016 University of Waterloo
3//
4// The contents of this file are covered under the licence agreement in the
5// file "LICENCE" distributed with Cforall.
6//
7// kernel.c --
8//
9// Author : Thierry Delisle
10// Created On : Tue Jan 17 12:27:26 2017
11// Last Modified By : Peter A. Buhr
12// Last Modified On : Mon Aug 31 07:08:20 2020
13// Update Count : 71
14//
15
16#define __cforall_thread__
17// #define __CFA_DEBUG_PRINT_RUNTIME_CORE__
18
19//C Includes
20#include <errno.h>
21#include <stdio.h>
22#include <signal.h>
23#include <unistd.h>
24
25//CFA Includes
26#include "kernel_private.hfa"
27#include "preemption.hfa"
28
29//Private includes
30#define __CFA_INVOKE_PRIVATE__
31#include "invoke.h"
32
33
34//-----------------------------------------------------------------------------
35// Some assembly required
36#if defined( __i386 )
37 // mxcr : SSE Status and Control bits (control bits are preserved across function calls)
38 // fcw : X87 FPU control word (preserved across function calls)
39 #define __x87_store \
40 uint32_t __mxcr; \
41 uint16_t __fcw; \
42 __asm__ volatile ( \
43 "stmxcsr %0\n" \
44 "fnstcw %1\n" \
45 : "=m" (__mxcr),\
46 "=m" (__fcw) \
47 )
48
49 #define __x87_load \
50 __asm__ volatile ( \
51 "fldcw %1\n" \
52 "ldmxcsr %0\n" \
53 ::"m" (__mxcr),\
54 "m" (__fcw) \
55 )
56
57#elif defined( __x86_64 )
58 #define __x87_store \
59 uint32_t __mxcr; \
60 uint16_t __fcw; \
61 __asm__ volatile ( \
62 "stmxcsr %0\n" \
63 "fnstcw %1\n" \
64 : "=m" (__mxcr),\
65 "=m" (__fcw) \
66 )
67
68 #define __x87_load \
69 __asm__ volatile ( \
70 "fldcw %1\n" \
71 "ldmxcsr %0\n" \
72 :: "m" (__mxcr),\
73 "m" (__fcw) \
74 )
75
76#elif defined( __arm__ )
77 #define __x87_store
78 #define __x87_load
79
80#elif defined( __aarch64__ )
81 #define __x87_store \
82 uint32_t __fpcntl[2]; \
83 __asm__ volatile ( \
84 "mrs x9, FPCR\n" \
85 "mrs x10, FPSR\n" \
86 "stp x9, x10, %0\n" \
87 : "=m" (__fpcntl) : : "x9", "x10" \
88 )
89
90 #define __x87_load \
91 __asm__ volatile ( \
92 "ldp x9, x10, %0\n" \
93 "msr FPSR, x10\n" \
94 "msr FPCR, x9\n" \
95 : "=m" (__fpcntl) : : "x9", "x10" \
96 )
97
98#else
99 #error unsupported hardware architecture
100#endif
101
102extern $thread * mainThread;
103extern processor * mainProcessor;
104
105//-----------------------------------------------------------------------------
106// Kernel Scheduling logic
107static $thread * __next_thread(cluster * this);
108static $thread * __next_thread_slow(cluster * this);
109static void __run_thread(processor * this, $thread * dst);
110static void __wake_one(cluster * cltr);
111static void wait(__bin_sem_t & this);
112
113static void push (__cluster_idles & idles, processor & proc);
114static void remove(__cluster_idles & idles, processor & proc);
115static [unsigned idle, unsigned total, * processor] query( & __cluster_idles idles );
116
117
118//=============================================================================================
119// Kernel Scheduling logic
120//=============================================================================================
121//Main of the processor contexts
122void main(processorCtx_t & runner) {
123 // Because of a bug, we couldn't initialized the seed on construction
124 // Do it here
125 __cfaabi_tls.rand_seed ^= rdtscl();
126 __cfaabi_tls.ready_rng.fwd_seed = 25214903917_l64u * (rdtscl() ^ (uintptr_t)&runner);
127 __tls_rand_advance_bck();
128
129 processor * this = runner.proc;
130 verify(this);
131
132 __cfadbg_print_safe(runtime_core, "Kernel : core %p starting\n", this);
133 #if !defined(__CFA_NO_STATISTICS__)
134 if( this->print_halts ) {
135 __cfaabi_bits_print_safe( STDOUT_FILENO, "Processor : %d - %s (%p)\n", this->id, this->name, (void*)this);
136 }
137 #endif
138
139 {
140 // Setup preemption data
141 preemption_scope scope = { this };
142
143 #if !defined(__CFA_NO_STATISTICS__)
144 unsigned long long last_tally = rdtscl();
145 #endif
146
147
148 __cfadbg_print_safe(runtime_core, "Kernel : core %p started\n", this);
149
150 $thread * readyThread = 0p;
151 MAIN_LOOP:
152 for() {
153 // Try to get the next thread
154 readyThread = __next_thread( this->cltr );
155
156 if( !readyThread ) {
157 readyThread = __next_thread_slow( this->cltr );
158 }
159
160 HALT:
161 if( !readyThread ) {
162 // Don't block if we are done
163 if( __atomic_load_n(&this->do_terminate, __ATOMIC_SEQ_CST) ) break MAIN_LOOP;
164
165 #if !defined(__CFA_NO_STATISTICS__)
166 __tls_stats()->ready.sleep.halts++;
167 #endif
168
169 // Push self to idle stack
170 push(this->cltr->idles, * this);
171
172 // Confirm the ready-queue is empty
173 readyThread = __next_thread_slow( this->cltr );
174 if( readyThread ) {
175 // A thread was found, cancel the halt
176 remove(this->cltr->idles, * this);
177
178 #if !defined(__CFA_NO_STATISTICS__)
179 __tls_stats()->ready.sleep.cancels++;
180 #endif
181
182 // continue the mai loop
183 break HALT;
184 }
185
186 #if !defined(__CFA_NO_STATISTICS__)
187 if(this->print_halts) {
188 __cfaabi_bits_print_safe( STDOUT_FILENO, "PH:%d - %lld 0\n", this->id, rdtscl());
189 }
190 #endif
191
192 wait( this->idle );
193
194 #if !defined(__CFA_NO_STATISTICS__)
195 if(this->print_halts) {
196 __cfaabi_bits_print_safe( STDOUT_FILENO, "PH:%d - %lld 1\n", this->id, rdtscl());
197 }
198 #endif
199
200 // We were woken up, remove self from idle
201 remove(this->cltr->idles, * this);
202
203 // DON'T just proceed, start looking again
204 continue MAIN_LOOP;
205 }
206
207 /* paranoid */ verify( readyThread );
208
209 // We found a thread run it
210 __run_thread(this, readyThread);
211
212 // Are we done?
213 if( __atomic_load_n(&this->do_terminate, __ATOMIC_SEQ_CST) ) break MAIN_LOOP;
214
215 #if !defined(__CFA_NO_STATISTICS__)
216 unsigned long long curr = rdtscl();
217 if(curr > (last_tally + 500000000)) {
218 __tally_stats(this->cltr->stats, __cfaabi_tls.this_stats);
219 last_tally = curr;
220 }
221 #endif
222 }
223
224 __cfadbg_print_safe(runtime_core, "Kernel : core %p stopping\n", this);
225 }
226
227 post( this->terminated );
228
229 if(this == mainProcessor) {
230 // HACK : the coroutine context switch expects this_thread to be set
231 // and it make sense for it to be set in all other cases except here
232 // fake it
233 __cfaabi_tls.this_thread = mainThread;
234 }
235
236 __cfadbg_print_safe(runtime_core, "Kernel : core %p terminated\n", this);
237}
238
239static int * __volatile_errno() __attribute__((noinline));
240static int * __volatile_errno() { asm(""); return &errno; }
241
242// KERNEL ONLY
243// runThread runs a thread by context switching
244// from the processor coroutine to the target thread
245static void __run_thread(processor * this, $thread * thrd_dst) {
246 /* paranoid */ verify( ! __preemption_enabled() );
247 /* paranoid */ verifyf( thrd_dst->state == Ready || thrd_dst->preempted != __NO_PREEMPTION, "state : %d, preempted %d\n", thrd_dst->state, thrd_dst->preempted);
248 /* paranoid */ verifyf( thrd_dst->link.next == 0p, "Expected null got %p", thrd_dst->link.next );
249 __builtin_prefetch( thrd_dst->context.SP );
250
251 $coroutine * proc_cor = get_coroutine(this->runner);
252
253 // set state of processor coroutine to inactive
254 verify(proc_cor->state == Active);
255 proc_cor->state = Blocked;
256
257 // Actually run the thread
258 RUNNING: while(true) {
259 thrd_dst->preempted = __NO_PREEMPTION;
260 thrd_dst->state = Active;
261
262 // Update global state
263 kernelTLS().this_thread = thrd_dst;
264
265 /* paranoid */ verify( ! __preemption_enabled() );
266 /* paranoid */ verify( kernelTLS().this_thread == thrd_dst );
267 /* paranoid */ verify( thrd_dst->curr_cluster == this->cltr );
268 /* paranoid */ verify( thrd_dst->context.SP );
269 /* paranoid */ verify( thrd_dst->state != Halted );
270 /* paranoid */ verifyf( ((uintptr_t)thrd_dst->context.SP) < ((uintptr_t)__get_stack(thrd_dst->curr_cor)->base ) || thrd_dst->curr_cor == proc_cor, "ERROR : Destination $thread %p has been corrupted.\n StackPointer too small.\n", thrd_dst ); // add escape condition if we are setting up the processor
271 /* paranoid */ verifyf( ((uintptr_t)thrd_dst->context.SP) > ((uintptr_t)__get_stack(thrd_dst->curr_cor)->limit) || thrd_dst->curr_cor == proc_cor, "ERROR : Destination $thread %p has been corrupted.\n StackPointer too large.\n", thrd_dst ); // add escape condition if we are setting up the processor
272 /* paranoid */ verify( 0x0D15EA5E0D15EA5Ep == thrd_dst->canary );
273
274
275
276 // set context switch to the thread that the processor is executing
277 __cfactx_switch( &proc_cor->context, &thrd_dst->context );
278 // when __cfactx_switch returns we are back in the processor coroutine
279
280 /* paranoid */ verify( 0x0D15EA5E0D15EA5Ep == thrd_dst->canary );
281 /* paranoid */ verifyf( ((uintptr_t)thrd_dst->context.SP) > ((uintptr_t)__get_stack(thrd_dst->curr_cor)->limit), "ERROR : Destination $thread %p has been corrupted.\n StackPointer too large.\n", thrd_dst );
282 /* paranoid */ verifyf( ((uintptr_t)thrd_dst->context.SP) < ((uintptr_t)__get_stack(thrd_dst->curr_cor)->base ), "ERROR : Destination $thread %p has been corrupted.\n StackPointer too small.\n", thrd_dst );
283 /* paranoid */ verify( thrd_dst->context.SP );
284 /* paranoid */ verify( thrd_dst->curr_cluster == this->cltr );
285 /* paranoid */ verify( kernelTLS().this_thread == thrd_dst );
286 /* paranoid */ verify( ! __preemption_enabled() );
287
288 // Reset global state
289 kernelTLS().this_thread = 0p;
290
291 // We just finished running a thread, there are a few things that could have happened.
292 // 1 - Regular case : the thread has blocked and now one has scheduled it yet.
293 // 2 - Racy case : the thread has blocked but someone has already tried to schedule it.
294 // 4 - Preempted
295 // In case 1, we may have won a race so we can't write to the state again.
296 // In case 2, we lost the race so we now own the thread.
297
298 if(unlikely(thrd_dst->preempted != __NO_PREEMPTION)) {
299 // The thread was preempted, reschedule it and reset the flag
300 __schedule_thread( thrd_dst );
301 break RUNNING;
302 }
303
304 if(unlikely(thrd_dst->state == Halting)) {
305 // The thread has halted, it should never be scheduled/run again
306 // finish the thread
307 __thread_finish( thrd_dst );
308 break RUNNING;
309 }
310
311 /* paranoid */ verify( thrd_dst->state == Active );
312 thrd_dst->state = Blocked;
313
314 // set state of processor coroutine to active and the thread to inactive
315 int old_ticket = __atomic_fetch_sub(&thrd_dst->ticket, 1, __ATOMIC_SEQ_CST);
316 switch(old_ticket) {
317 case TICKET_RUNNING:
318 // This is case 1, the regular case, nothing more is needed
319 break RUNNING;
320 case TICKET_UNBLOCK:
321 // This is case 2, the racy case, someone tried to run this thread before it finished blocking
322 // In this case, just run it again.
323 continue RUNNING;
324 default:
325 // This makes no sense, something is wrong abort
326 abort();
327 }
328 }
329
330 // Just before returning to the processor, set the processor coroutine to active
331 proc_cor->state = Active;
332
333 /* paranoid */ verify( ! __preemption_enabled() );
334}
335
336// KERNEL_ONLY
337void returnToKernel() {
338 /* paranoid */ verify( ! __preemption_enabled() );
339 $coroutine * proc_cor = get_coroutine(kernelTLS().this_processor->runner);
340 $thread * thrd_src = kernelTLS().this_thread;
341
342 #if !defined(__CFA_NO_STATISTICS__)
343 struct processor * last_proc = kernelTLS().this_processor;
344 #endif
345
346 // Run the thread on this processor
347 {
348 int local_errno = *__volatile_errno();
349 #if defined( __i386 ) || defined( __x86_64 )
350 __x87_store;
351 #endif
352 /* paranoid */ verify( proc_cor->context.SP );
353 /* paranoid */ verify( 0x0D15EA5E0D15EA5Ep == thrd_src->canary );
354 __cfactx_switch( &thrd_src->context, &proc_cor->context );
355 /* paranoid */ verify( 0x0D15EA5E0D15EA5Ep == thrd_src->canary );
356 #if defined( __i386 ) || defined( __x86_64 )
357 __x87_load;
358 #endif
359 *__volatile_errno() = local_errno;
360 }
361
362 #if !defined(__CFA_NO_STATISTICS__)
363 if(last_proc != kernelTLS().this_processor) {
364 __tls_stats()->ready.threads.migration++;
365 }
366 #endif
367
368 /* paranoid */ verify( ! __preemption_enabled() );
369 /* paranoid */ verifyf( ((uintptr_t)thrd_src->context.SP) < ((uintptr_t)__get_stack(thrd_src->curr_cor)->base ), "ERROR : Returning $thread %p has been corrupted.\n StackPointer too small.\n", thrd_src );
370 /* paranoid */ verifyf( ((uintptr_t)thrd_src->context.SP) > ((uintptr_t)__get_stack(thrd_src->curr_cor)->limit), "ERROR : Returning $thread %p has been corrupted.\n StackPointer too large.\n", thrd_src );
371}
372
373//-----------------------------------------------------------------------------
374// Scheduler routines
375// KERNEL ONLY
376void __schedule_thread( $thread * thrd ) {
377 /* paranoid */ verify( ! __preemption_enabled() );
378 /* paranoid */ verify( kernelTLS().this_proc_id );
379 /* paranoid */ verify( thrd );
380 /* paranoid */ verify( thrd->state != Halted );
381 /* paranoid */ verify( thrd->curr_cluster );
382 /* paranoid */ #if defined( __CFA_WITH_VERIFY__ )
383 /* paranoid */ if( thrd->state == Blocked || thrd->state == Start ) assertf( thrd->preempted == __NO_PREEMPTION,
384 "Error inactive thread marked as preempted, state %d, preemption %d\n", thrd->state, thrd->preempted );
385 /* paranoid */ if( thrd->preempted != __NO_PREEMPTION ) assertf(thrd->state == Active,
386 "Error preempted thread marked as not currently running, state %d, preemption %d\n", thrd->state, thrd->preempted );
387 /* paranoid */ #endif
388 /* paranoid */ verifyf( thrd->link.next == 0p, "Expected null got %p", thrd->link.next );
389 /* paranoid */ verify( 0x0D15EA5E0D15EA5Ep == thrd->canary );
390
391
392 if (thrd->preempted == __NO_PREEMPTION) thrd->state = Ready;
393
394 ready_schedule_lock();
395 // Dereference the thread now because once we push it, there is not guaranteed it's still valid.
396 struct cluster * cl = thrd->curr_cluster;
397
398 // push the thread to the cluster ready-queue
399 push( cl, thrd );
400
401 // variable thrd is no longer safe to use
402
403 // wake the cluster using the save variable.
404 __wake_one( cl );
405 ready_schedule_unlock();
406
407 /* paranoid */ verify( ! __preemption_enabled() );
408}
409
410// KERNEL ONLY
411static inline $thread * __next_thread(cluster * this) with( *this ) {
412 /* paranoid */ verify( ! __preemption_enabled() );
413 /* paranoid */ verify( kernelTLS().this_proc_id );
414
415 ready_schedule_lock();
416 $thread * thrd = pop( this );
417 ready_schedule_unlock();
418
419 /* paranoid */ verify( kernelTLS().this_proc_id );
420 /* paranoid */ verify( ! __preemption_enabled() );
421 return thrd;
422}
423
424// KERNEL ONLY
425static inline $thread * __next_thread_slow(cluster * this) with( *this ) {
426 /* paranoid */ verify( ! __preemption_enabled() );
427 /* paranoid */ verify( kernelTLS().this_proc_id );
428
429 ready_schedule_lock();
430 $thread * thrd = pop_slow( this );
431 ready_schedule_unlock();
432
433 /* paranoid */ verify( kernelTLS().this_proc_id );
434 /* paranoid */ verify( ! __preemption_enabled() );
435 return thrd;
436}
437
438void unpark( $thread * thrd ) {
439 if( !thrd ) return;
440
441 int old_ticket = __atomic_fetch_add(&thrd->ticket, 1, __ATOMIC_SEQ_CST);
442 switch(old_ticket) {
443 case TICKET_RUNNING:
444 // Wake won the race, the thread will reschedule/rerun itself
445 break;
446 case TICKET_BLOCKED:
447 /* paranoid */ verify( ! thrd->preempted != __NO_PREEMPTION );
448 /* paranoid */ verify( thrd->state == Blocked );
449
450 {
451 /* paranoid */ verify( publicTLS_get(this_proc_id) );
452 bool full = publicTLS_get(this_proc_id)->full_proc;
453 if(full) disable_interrupts();
454
455 /* paranoid */ verify( ! __preemption_enabled() );
456
457 // Wake lost the race,
458 __schedule_thread( thrd );
459
460 /* paranoid */ verify( ! __preemption_enabled() );
461
462 if(full) enable_interrupts( __cfaabi_dbg_ctx );
463 /* paranoid */ verify( publicTLS_get(this_proc_id) );
464 }
465
466 break;
467 default:
468 // This makes no sense, something is wrong abort
469 abort("Thread %p (%s) has mismatch park/unpark\n", thrd, thrd->self_cor.name);
470 }
471}
472
473void park( void ) {
474 /* paranoid */ verify( __preemption_enabled() );
475 disable_interrupts();
476 /* paranoid */ verify( ! __preemption_enabled() );
477 /* paranoid */ verify( kernelTLS().this_thread->preempted == __NO_PREEMPTION );
478
479 returnToKernel();
480
481 /* paranoid */ verify( ! __preemption_enabled() );
482 enable_interrupts( __cfaabi_dbg_ctx );
483 /* paranoid */ verify( __preemption_enabled() );
484
485}
486
487extern "C" {
488 // Leave the thread monitor
489 // last routine called by a thread.
490 // Should never return
491 void __cfactx_thrd_leave() {
492 $thread * thrd = active_thread();
493 $monitor * this = &thrd->self_mon;
494
495 // Lock the monitor now
496 lock( this->lock __cfaabi_dbg_ctx2 );
497
498 disable_interrupts();
499
500 /* paranoid */ verify( ! __preemption_enabled() );
501 /* paranoid */ verify( thrd->state == Active );
502 /* paranoid */ verify( 0x0D15EA5E0D15EA5Ep == thrd->canary );
503 /* paranoid */ verify( kernelTLS().this_thread == thrd );
504 /* paranoid */ verify( thrd->context.SP );
505 /* paranoid */ verifyf( ((uintptr_t)thrd->context.SP) > ((uintptr_t)__get_stack(thrd->curr_cor)->limit), "ERROR : $thread %p has been corrupted.\n StackPointer too large.\n", thrd );
506 /* paranoid */ verifyf( ((uintptr_t)thrd->context.SP) < ((uintptr_t)__get_stack(thrd->curr_cor)->base ), "ERROR : $thread %p has been corrupted.\n StackPointer too small.\n", thrd );
507
508 thrd->state = Halting;
509 if( TICKET_RUNNING != thrd->ticket ) { abort( "Thread terminated with pending unpark" ); }
510 if( thrd != this->owner ) { abort( "Thread internal monitor has incorrect owner" ); }
511 if( this->recursion != 1) { abort( "Thread internal monitor has unbalanced recursion" ); }
512
513 // Leave the thread
514 returnToKernel();
515
516 // Control flow should never reach here!
517 abort();
518 }
519}
520
521// KERNEL ONLY
522bool force_yield( __Preemption_Reason reason ) {
523 /* paranoid */ verify( __preemption_enabled() );
524 disable_interrupts();
525 /* paranoid */ verify( ! __preemption_enabled() );
526
527 $thread * thrd = kernelTLS().this_thread;
528 /* paranoid */ verify(thrd->state == Active);
529
530 // SKULLDUGGERY: It is possible that we are preempting this thread just before
531 // it was going to park itself. If that is the case and it is already using the
532 // intrusive fields then we can't use them to preempt the thread
533 // If that is the case, abandon the preemption.
534 bool preempted = false;
535 if(thrd->link.next == 0p) {
536 preempted = true;
537 thrd->preempted = reason;
538 returnToKernel();
539 }
540
541 /* paranoid */ verify( ! __preemption_enabled() );
542 enable_interrupts_noPoll();
543 /* paranoid */ verify( __preemption_enabled() );
544
545 return preempted;
546}
547
548//=============================================================================================
549// Kernel Idle Sleep
550//=============================================================================================
551extern "C" {
552 char * strerror(int);
553}
554#define CHECKED(x) { int err = x; if( err != 0 ) abort("KERNEL ERROR: Operation \"" #x "\" return error %d - %s\n", err, strerror(err)); }
555
556static void wait(__bin_sem_t & this) with( this ) {
557 verify(__cfaabi_dbg_in_kernel());
558 CHECKED( pthread_mutex_lock(&lock) );
559 while(val < 1) {
560 pthread_cond_wait(&cond, &lock);
561 }
562 val -= 1;
563 CHECKED( pthread_mutex_unlock(&lock) );
564}
565
566static bool post(__bin_sem_t & this) with( this ) {
567 bool needs_signal = false;
568
569 CHECKED( pthread_mutex_lock(&lock) );
570 if(val < 1) {
571 val += 1;
572 pthread_cond_signal(&cond);
573 needs_signal = true;
574 }
575 CHECKED( pthread_mutex_unlock(&lock) );
576
577 return needs_signal;
578}
579
580#undef CHECKED
581
582// Wake a thread from the front if there are any
583static void __wake_one(cluster * this) {
584 /* paranoid */ verify( ! __preemption_enabled() );
585 /* paranoid */ verify( ready_schedule_islocked() );
586
587 // Check if there is a sleeping processor
588 processor * p;
589 unsigned idle;
590 unsigned total;
591 [idle, total, p] = query(this->idles);
592
593 // If no one is sleeping, we are done
594 if( idle == 0 ) return;
595
596 // We found a processor, wake it up
597 post( p->idle );
598
599 #if !defined(__CFA_NO_STATISTICS__)
600 __tls_stats()->ready.sleep.wakes++;
601 #endif
602
603 /* paranoid */ verify( ready_schedule_islocked() );
604 /* paranoid */ verify( ! __preemption_enabled() );
605
606 return;
607}
608
609// Unconditionnaly wake a thread
610void __wake_proc(processor * this) {
611 __cfadbg_print_safe(runtime_core, "Kernel : waking Processor %p\n", this);
612
613 disable_interrupts();
614 /* paranoid */ verify( ! __preemption_enabled() );
615 post( this->idle );
616 enable_interrupts( __cfaabi_dbg_ctx );
617}
618
619static void push (__cluster_idles & this, processor & proc) {
620 /* paranoid */ verify( ! __preemption_enabled() );
621 lock( this );
622 this.idle++;
623 /* paranoid */ verify( this.idle <= this.total );
624
625 insert_first(this.list, proc);
626 unlock( this );
627 /* paranoid */ verify( ! __preemption_enabled() );
628}
629
630static void remove(__cluster_idles & this, processor & proc) {
631 /* paranoid */ verify( ! __preemption_enabled() );
632 lock( this );
633 this.idle--;
634 /* paranoid */ verify( this.idle >= 0 );
635
636 remove(proc);
637 unlock( this );
638 /* paranoid */ verify( ! __preemption_enabled() );
639}
640
641static [unsigned idle, unsigned total, * processor] query( & __cluster_idles this ) {
642 for() {
643 uint64_t l = __atomic_load_n(&this.lock, __ATOMIC_SEQ_CST);
644 if( 1 == (l % 2) ) { Pause(); continue; }
645 unsigned idle = this.idle;
646 unsigned total = this.total;
647 processor * proc = &this.list`first;
648 // Compiler fence is unnecessary, but gcc-8 and older incorrectly reorder code without it
649 asm volatile("": : :"memory");
650 if(l != __atomic_load_n(&this.lock, __ATOMIC_SEQ_CST)) { Pause(); continue; }
651 return [idle, total, proc];
652 }
653}
654
655//=============================================================================================
656// Unexpected Terminating logic
657//=============================================================================================
658void __kernel_abort_msg( char * abort_text, int abort_text_size ) {
659 $thread * thrd = __cfaabi_tls.this_thread;
660
661 if(thrd) {
662 int len = snprintf( abort_text, abort_text_size, "Error occurred while executing thread %.256s (%p)", thrd->self_cor.name, thrd );
663 __cfaabi_bits_write( STDERR_FILENO, abort_text, len );
664
665 if ( &thrd->self_cor != thrd->curr_cor ) {
666 len = snprintf( abort_text, abort_text_size, " in coroutine %.256s (%p).\n", thrd->curr_cor->name, thrd->curr_cor );
667 __cfaabi_bits_write( STDERR_FILENO, abort_text, len );
668 }
669 else {
670 __cfaabi_bits_write( STDERR_FILENO, ".\n", 2 );
671 }
672 }
673 else {
674 int len = snprintf( abort_text, abort_text_size, "Error occurred outside of any thread.\n" );
675 __cfaabi_bits_write( STDERR_FILENO, abort_text, len );
676 }
677}
678
679int __kernel_abort_lastframe( void ) __attribute__ ((__nothrow__)) {
680 return get_coroutine(__cfaabi_tls.this_thread) == get_coroutine(mainThread) ? 4 : 2;
681}
682
683static __spinlock_t kernel_debug_lock;
684
685extern "C" {
686 void __cfaabi_bits_acquire() {
687 lock( kernel_debug_lock __cfaabi_dbg_ctx2 );
688 }
689
690 void __cfaabi_bits_release() {
691 unlock( kernel_debug_lock );
692 }
693}
694
695//=============================================================================================
696// Kernel Utilities
697//=============================================================================================
698//-----------------------------------------------------------------------------
699// Debug
700__cfaabi_dbg_debug_do(
701 extern "C" {
702 void __cfaabi_dbg_record_lock(__spinlock_t & this, const char prev_name[]) {
703 this.prev_name = prev_name;
704 this.prev_thrd = kernelTLS().this_thread;
705 }
706 }
707)
708
709//-----------------------------------------------------------------------------
710// Debug
711bool threading_enabled(void) __attribute__((const)) {
712 return true;
713}
714
715//-----------------------------------------------------------------------------
716// Statistics
717#if !defined(__CFA_NO_STATISTICS__)
718 void print_halts( processor & this ) {
719 this.print_halts = true;
720 }
721
722 void print_stats_now( cluster & this, int flags ) {
723 __print_stats( this.stats, this.print_stats, "Cluster", this.name, (void*)&this );
724 }
725
726 extern int __print_alarm_stats;
727 void print_alarm_stats() {
728 __print_alarm_stats = -1;
729 }
730#endif
731// Local Variables: //
732// mode: c //
733// tab-width: 4 //
734// End: //
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